Here's a breakdown:
* Grammatical function: Suffixes can modify the grammatical role of a word. For example, adding "-ing" to a verb creates a present participle (e.g., "walk" becomes "walking"), and adding "-er" to a verb creates a noun denoting a person or thing that performs the action (e.g., "teach" becomes "teacher").
* Meaning: Suffixes can also alter the meaning of a word. Adding "-ness" to an adjective creates a noun that represents the quality or state of being (e.g., "happy" becomes "happiness"). Adding "-ful" to a noun or adjective creates an adjective meaning "full of" (e.g., "joy" becomes "joyful").
Here are some examples:
* -ing: walk ing, play ing
* -er: teach er, sing er
* -ness: happy ness, kind ness
* -ful: hope ful, care ful
* -ly: quick ly, happy ly
Adding suffixes is a common way to create new words in English and is a key part of understanding word formation.